Related Products: Fix hardcoded limit product (#9407)

* fix hardcoded limit product

* improve readibility

Author: gigitux

src/BlockTypes/RelatedProducts.php

@@ -87,7 +87,7 @@ public function build_query( $query ) {
 			return $query;
 		}
 
-		$related_products_ids = $this->get_related_products_ids();
+		$related_products_ids = $this->get_related_products_ids( $query['posts_per_page'] );
 		if ( count( $related_products_ids ) < 1 ) {
 			return array();
 		}
@@ -113,11 +113,12 @@ public function render_block( string $content, array $block ) {
 			return $content;
 		}
 
+		// If there are no related products, render nothing.
 		$related_products_ids = $this->get_related_products_ids();
-
 		if ( count( $related_products_ids ) < 1 ) {
 			return '';
 		}
+
 		return $content;
 	}
 
@@ -142,14 +143,15 @@ private function is_related_products_block( $block ) {
 	 * Get related products ids.
 	 * The logic is copied from the core function woocommerce_related_products. https://github.com/woocommerce/woocommerce/blob/ca49caabcba84ce9f60a03c6d3534ec14b350b80/plugins/woocommerce/includes/wc-template-functions.php/#L2039-L2074
 	 *
+	 * @param number $product_per_page Products per page.
 	 * @return array Products ids.
 	 */
-	private function get_related_products_ids() {
+	private function get_related_products_ids( $product_per_page = 5 ) {
 		global $post;
 
 		$product = wc_get_product( $post->ID );
 
-		$related_products = array_filter( array_map( 'wc_get_product', wc_get_related_products( $product->get_id(), 5, $product->get_upsell_ids() ) ), 'wc_products_array_filter_visible' );
+		$related_products = array_filter( array_map( 'wc_get_product', wc_get_related_products( $product->get_id(), $product_per_page, $product->get_upsell_ids() ) ), 'wc_products_array_filter_visible' );
 		$related_products = wc_products_array_orderby( $related_products, 'rand', 'desc' );
 
 		$related_product_ids = array_map(